Answer:
D. 4 root 113
Explanation:
we have to use Pythagorean Theorem which is
a^2 + b^2 = c^2
where a and b are legs of the triangle that are 45° apart and c is the hypotenuse.
now we just plug in our values.
a^2 + (9)^2 = (47)^2
a^2 + 81 = 2209
now we're gonna solve for A (the missing side)
a^2 = 2128
now we square root both sides to undo the square on A
root(a^2) = root(2128)
because 2128 isn't a pretty root, we have to simplify it
a = 4 root(133)